/Engine/Source/Editor/UnrealEd/Public/EditorLevelUtils.h
Adds the named level package to the world at the given position. Does nothing if the level already exists in the world.
The new level, or NULL if the level couldn't added.
static [ULevelStreaming](API\Runtime\Engine\Engine\ULevelStreaming) * K2_AddLevelToWorldWithTransform ( [UWorld](API\Runtime\Engine\Engine\UWorld) * World, const [FString](API\Runtime\Core\Containers\FString) & LevelPackageName, [TSubclassOf](API\Runtime\CoreUObject\Templates\TSubclassOf)< [ULevelStreaming](API\Runtime\Engine\Engine\ULevelStreaming) > LevelStreamingClass, const FTransform & LevelTransform )